Tissue graft fixation

This application is a divisional of U.S. patent application Ser. No. 11/313,716, now U.S. Pat. No. 8,323,338, filed on Dec. 22, 2005, entitled TISSUE GRAFT FIXATION. The contents of the prior application are incorporated herein by reference in their entirety.

This invention relates to tissue graft fixation.

An anterior cruciate ligament (ACL) that has ruptured and is non-repairable is generally replaced arthroscopically by a tissue graft. The tissue graft can be harvested from a portion of a patellar tendon having so called “bone blocks” at each end, and from the semitendonosis and gracilis. Alternatively, the tissue graft can be formed from synthetic materials or from a combination of synthetic and natural materials.

The replacement tissue graft is implanted by securing one end of the tissue graft in a socket formed in a passage within the femur, and passing the other end of the graft through a passage formed in the tibia. Generally, sutures are used to affix each end of the tissue graft to a fastener (e.g., an interference screw or a post), which is then secured to the bone.

It is also known to use a graft fixation member, e.g., a fixation button, to secure the tissue graft at the femoral cortex, as described in U.S. Pat. No. 5,306,301 (“the '301 patent”) hereby incorporated by reference in its entirety. When using a fixation button, the femoral passage generally includes a relatively larger diameter portion for receiving the graft, and a smaller diameter, passing channel near the femoral cortex for receiving a length of suture that runs from the tissue graft to the fixation button. By measuring the total length of the femoral passage and the length of the larger diameter portion of the femoral passage, the surgeon determines the appropriate length of suture material for attaching the fixation button to the tissue graft.

According to one aspect, a surgical device includes a member having first and second opposing surfaces. The member includes an intermediate portion in which the first surface has a recessed surface portion. The intermediate portion defines a hole extending from the recessed surface portion to the second surface. End portions extend from the intermediate portion, and each end portion defines a hole extending from the first surface to the second surface.

Embodiments of this aspect may include one or more of the following features.

The surgical device includes a second member sized to be received within the recessed surface portion. The intermediate portion defines two additional holes extending from the recessed surface portion to the second surface. The member has a tapered surface portion on the second surface. The intermediate portion hole is elongated.

According to another aspect, a surgical device includes first and second members. The first member has first and second opposing surfaces, a recessed surface portion in the first surface, and a hole extending from the recessed surface portion to the second surface. The second member defines a hole and is configured to be received within the recessed portion of the first member.

Embodiments of this aspect may include one or more of the following features.

The holes are positioned to be axially aligned when the second member is received within the recessed portion. The recessed portion is configured to provide a snap-fit or an interference-fit with the second member. The surgical device includes a suture extending through the holes. The first member defines at least two additional holes, for example, a total of five holes. The second member defines three additional holes. The first member has a tapered surface portion on the second surface of the member.

According to another aspect, a method includes locating a tissue fixation device at an opening to a bone hole, the tissue fixation device being coupled to a tissue graft by a flexible member, for example, suture, and increasing the size of the tissue fixation device by placing the tissue fixation device within a larger device having a hole for receiving the flexible member. This aspect may include increasing the size of the tissue fixation device prior to locating the tissue fixation device at the opening.

Advantages may include one or more of the following: the continuation of an endoscopic procedure despite perforation of the cortex; use with outside in femoral drilling as is done in pediatric cases to avoid crossing the epiphysis; use as a fast primary to avoid the need for using two drills and measuring of the EndoButton CL length; and coverage of a 6-10 mm tunnel.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

FIG. 1 is an illustration of a tissue graft secured within the knee by a graft fixation member.

FIG. 2A is an exploded, perspective view of the graft fixation member of FIG. 1 .

FIG. 2B is an end view of the graft fixation member of FIG. 1 .

FIG. 3A is an end view of a washer of the graft fixation member of FIG. 1 .

FIG. 3B is a side view of the washer of FIG. 3A .

FIG. 4A is a perspective view of the graft fixation member of FIG. 1 shown threaded with suture.

FIG. 4B is an illustration of the graft fixation member coupled to a tissue graft, with the washer shown in dashed line.

FIG. 5 illustrates drilling a femoral passage within a knee.

FIG. 6 shows engagement of the graft fixation member with a suture retrieval device for pulling the graft fixation member through the femoral passage.

FIG. 7A is perspective view of a washer according to another embodiment.

FIG. 7B is a side view of the washer of FIG. 7A .

FIG. 7C is a sectional view taken along line 7 C- 7 C in FIG. 7B .

FIG. 8 is a side view of a washer according to another embodiment.

FIG. 9 is a side view of a washer according to another embodiment.

FIG. 10A is perspective view of a washer according to another embodiment.

FIG. 10B is an end view of the washer of FIG. 10A .

FIG. 10C is a sectional view taken along line 10 C- 10 C in FIG. 10B .

Referring to FIG. 1 , a fixation member 90 connected to a bone block 22 of a tissue graft 20 by suture 30 is positioned over the opening 17 of a femoral passage 14 to secure the graft 20 in the femoral passage 14 . Fixation member 90 includes a first member, e.g., a button 100 , received within a second member, e.g., a washer 110 . In contrast to techniques that include drilling a passing channel in the femur, such as described in the '301 patent, fixation member 90 enables femoral passage 14 to have a substantially uniform diameter, thus eliminating the added steps of measuring and drilling the relatively smaller passing channel.

Referring to FIGS. 2A-3B , the washer 110 has a generally elongate shape with an intermediate portion 111 and end portions 112 extending from the intermediate portion 111 . Washer 110 has first and second opposing surfaces 114 , 115 , and the intermediate portion 111 has a recessed surface portion 116 for receiving button 100 . Intermediate portion 111 has a hole 120 , preferably centrally located, extending from the recessed surface portion 116 to the second surface 115 for receiving the graft tissue suture 30 . The washer 110 defines four additional holes 125 , one hole 125 b in each of the end portions 112 , and two inner holes 125 a in intermediate portion 111 on either side of central hole 120 , for receiving a pull suture 45 ( FIG. 4 ). Holes 125 extend from the first surface 114 to the second surface 115 of the washer.

The washer surface 115 is tapered from end portions 112 to intermediate portion 111 (such as shown in FIG. 7C ), and can also be tapered along the entire distance between end portions 112 and the intermediate portion 111 as shown in FIGS. 7C and 10C . It is the intermediate portion 111 of the washer that is received within the opening 17 of the femoral passage 14 during use with the washer surface 115 facing the femoral passage. The taper permits fixation member 90 to securely engage the opening 17 of the femoral passage 14 with the washer end portions 112 against the bone surface, while maintaining a low profile relative to bone surface. The taper facilitates a tight fit between the fixation member 90 and passage openings 17 having a range of diameters. Thus, the tapered reduces the need to precisely match the size of the graft fixation member with the femoral passage opening. However, the washer need not include the tapered portion.

The button 100 defines holes 105 , four holes being shown. The two central holes 105 a align with the washer central hole 120 , and the two end holes 105 b each align with one of the inner washer holes 125 a when the button 100 is positioned within the washer recess 116 . The elongated washer 110 has a length L, a width W and a thickness T, for example, for an adult femur, the washer 110 has a length of about 15-30 mm, for example, 20 mm, a width of about 6-10 mm, for example, 6 mm, and a thickness of about 1-4 mm, for example, 3 mm, to bridge the span of a femoral passage 14 and provide sufficient rigidity to adequately tension sutures holding a tissue graft 20 while maintaining a relatively low profile with respect to the surface of the femur 12 . The washer recess 116 is dimensioned to receive the button 100 by, for example, a snap-fit or interference-fit, and has a depth corresponding to the thickness of the button such that the button is flush with the surface 114 of the washer 110 .

Referring to FIGS. 4A and 4B , the button 100 /washer 110 combination is provided with two closed loops of suture 30 extending through washer hole 120 and threaded through button holes 105 a . Graft fixation member 90 is also provided with one suture 45 threaded through one of the washer holes 125 b , back through the adjacent washer hole 125 a , and through the corresponding button hole 105 b , and a second suture 45 similarly threaded through the holes on the other side of the washer and button. Alternatively, operating room personnel can thread the sutures 45 . FIG. 6 shows an alternative threading of sutures 45 , with one suture 45 threaded through each of the washer holes 125 b . Here, washer holes 125 a and button holes 105 b are not used.

Referring to FIGS. 5 and 6 , in use, a femoral hole 17 of substantially uniform diameter is drilled using a drill 40 . To pull the graft fixation member 90 and tissue graft 20 through the tibia and femur passages, a suture retrieving device, such as a passing pin 50 , is used to removably engage the free ends of sutures 44 and pull the fixation member 90 through the knee 10 .

Referring to FIG. 1 , once the fixation member 90 has been pulled through the femoral passage 14 , the surgeon positions the fixation member 90 transversely to the femoral passage 14 and across the opening 17 . To complete the fixation of the tissue graft, the fixation member 90 is secured against the femur 12 by attaching the tissue graft 20 to the tibia 13 and tensioning the tissue graft 20 and the closed-loop suture 30 according to methods described in the '301 patent.

Other embodiments are within the scope of the following claims. For example, other embodiments can include washers appropriately sized and shaped to receive buttons with a variety of geometries. Referring to FIGS. 7A-7C , rather than including both the central hole 120 and suture holes 125 a within the recess 116 , a washer 710 includes only a central hole 720 within a recess 716 sized and shaped to accommodate suture from the four holes 105 a and 105 b of the button. Hole 720 includes two side extending openings 722 , 724 for receiving suture from holes 105 b . The washer 710 includes suture holes 725 b in end portions 712 of the washer 710 .

Referring to FIG. 8 , in another embodiment, a washer 810 includes only an elongated, central hole 820 within a recess 816 , and side holes 825 B. Referring to FIG. 9 , in another embodiment, a washer 910 includes a central hole 920 and side holes 925 B, analogous to holes 720 and 725 b in washer 710 , but additionally includes holes 925 a . In another embodiment ( FIGS. 10A-10C ), a washer 1010 includes round suture holes 1025 b in end portions 912 , and oblong suture holes 1025 at recess portion 1016 adjacent to a central hole 1020 .

Although the aforementioned embodiments have been described in connection with procedures having a single, uniformly-sized femoral passage, the graft fixation member can be applied to procedures in which a smaller passing channel is formed in the femoral passage. For example, the creation of a smaller passing channel may be desirable in some patients, such as child whose bones are growing or an elderly patient without sufficient bone density to accommodate a relatively large femoral passage 14 . In these cases, the graft fixation member advantageously increases the surface area of the bone over which tension is applied.

The recess of the washer can be sized and shaped to completely or partially receive the button. Washers can be provided having different sized and/or shaped recesses to accommodate different buttons. For example, the recessed portion 116 of washer 110 can be sized and shaped to receive the fixation buttons described in U.S. Pat. No. 6,533,802 and U.S. patent application Ser. No. 10/895,266, filed Jul. 20, 2004, published as US 2005-0038427 A1, both incorporated herein in their entirety.

The closed-loop suture 30 can be, but is not limited to, a continuous loop made from polyester, a strand of suture tied in a loop, or a piece of polyester closure tape (e.g. Marselene™ from Ethicon Inc., Cincinnati, Ohio) tied in a loop.

The graft fixation member is formed from a biocompatible material such as titanium or PEEK.

The fixation member can be used with tissue grafts other than those with bone blocks, for example, harvested tissue graft without bone blocks, and tissue grafts formed from synthetic materials or from a combination of synthetic and natural materials.

A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made. For example, the aforementioned tissue graft fixation procedure may be applicable to other parts of the knee or other parts of the human body requiring tissue reconstruction. Accordingly, other embodiments are within the scope of the following claims.